It's impossible to know who will be the next beyonce or bieber but this guy had it. The sold out concerts, the tour bus, the slick videos with the hollywood model. But there was a big lie in those lyrics, here's chris connelly. &#9834; Reporter: As the lead singer for his band lights over paris, robert mawhinney wanted to be a rock star in the worst way. In this, he succeeded. He fulfilled his every rock n roll fantasy. Starring in sexy music videos, throwing wild, all-night parties at his luxury dwellings across los angeles. Including this $10-g's a month riot house in the hollywood hills. I have no idea where all the women came from. Loud party, misdemeanor. Hey, if it's not a, felony, let's keep partying! Reporter: Hitting the road with no expense spared. Spraying pricey champagne off the balcony of a penthouse suite. Deploying an in-concert money gun. He really liked the idea of shooting money into the crowd. Reporter: Even building this one-of-a-kind fabulously appointed $750,000 tour bus. It's called the "futureliner." This window here will go all the way around, like, 270 degrees. Really cool. Over here's just gonna be, you know, a lounge area, tv on the wall right here. Reporter: He had all this, and a key rock-star pre-requisite: Tons of apparent self-confidence. But most of all, robb mawhinney had serious stacks of cash. I basically had an endless bank account with, you know, money inside of it. Reporter: What no one realized, until the bill came due, was that all of it, the whole star-spangled shebang, was not what it seemed to be. A big lie? Right from the get-go. A complete lie. Reporter: As a teen in orange county, mawhinney idolized high-energy rock bands who'd climbed the ladder to multi-platinum success. Like blink-182. But by his mid-20s, he & his homeboys weren't going anywhere. And lights over paris had no recording contract, no gigs, no merch. Yet somehow, robb had cheddar like a cracker barrel. Brimming with bank and the urge to spend it, on things like trips to new york city. It was crazy. There was a lot of booze, a lot of champagne, and the hotel suite ended up getting trashed at the end of the trip, so -- Reporter: Brian king had responded to a craigslist ad to be a videographer for lights over paris. What he saw in ny? No rock, but a whole lotta high rollin'. any rock & roll. He got a bunch of his buddies from la, they all flew into new york. One of their friends, they got him to streak through several blocks in soho. Reporter: Ah, but then the 5'6" frontman, now calling himself robb talllll, because why not? Landed in an l.A. Recording studio, doing a lights over paris album with professional musicians. Even a string section in support. One small problem -- he didn't have a label. And he'd never made a record before. A lot of people didn't really know what the deal was with rob. People just thought he was a really wealthy guy who wanted to be the next blink 182. Reporter: But with his blink-and-you-missed-it rock resume, robb dug deep for top-shelf help. A choreographer, phat rhymes from the rap star "game" -- and a six-figure music video. Cast from a pool of women to star as the femme fatale in lights over paris' "turn off the lights" stunning olivia hardt, scream queen of syfy's sharknado-esque tv-movie arachnoquake, spotted a lag in robb's swag. I got in the transportation van. And I knew that it was rob sitting right next to me, the guy that I was gonna be kissing that day. But he did not say a word to me. I think he was a little bit nervous. We can't make out with your teeth on. No, I'm just saying, for that part -- I mean, after the scene, he's like, that wasn't as, as scary as i thought it was gonna be." It was definitely a first for him, and he let me know that. Reporter: Olivia says she soon began to wonder about the source of robb's boundless bankroll. What did he say to you when you asked, "where is all this money coming from?" He told me that his grandfather had passed away that he received some inheritance. I was working with my grandfather. We'd buy lots and we'd build houses on 'em. It succeed ed and I made a couple bucks. It was a big lie? Yeah. I know that now. He had a problem with people thinking he just walked into having money. Reporter: In fact, robb had walked into banks and asked for millions in loans. The loan officer in the bank, asked mr. Mawhinney to provide proof of the statements that he made in the application, regarding his assets and his income. To loan officers he produced documents listing $8 million in stocks. And this accountant-prepared 1040. 4 different banks issued mawhinney loans to the tune of $11 million. But as lights over paris toured, it turned out that there are some things that money can't buy. Like fans. A couple girls told me about a sold out show, about this band, lights over paris. And so I wanted to come see what was going on with this band. Reporter: When rock photographer derek brad got to the north star bar in philadelphia, those on stage nearly outnumbered the audience. There was actually less than 10 people here. Reporter: It was sold out, because robb tall had bought all the tickets. Only the lights over paris street team couldn't even give them away. Then on october 1, 2011 the night they were to play the roxy, on la's sunset strip, robb didn't even show up. Sending a dj in his place instead. Why wasn't robb doing the show? I guess his high school reunion was that night? Reporter: And how about this for a remix. That's the dj getting served, onstage, with legal papers intended for robb, now way behind on his riot house rent. The party, the parties, were over. One year later robb was arrested in miami. The $11 million in loans and the documents he submitted to get them? Yeah, about those -- the tax return was entirely fake. And the cpa whose name was used on the letter, again we interviewed him, and he said, again "robert mawhinney? Never heard of him." Reporter: Then there was that big-money-in-stocks statement from schwab. This is what was submitted to the . And yes it says here, $8 million, total account value. That's correct. And then we obtained from charles schwab itself, here's the account statement. Same account for the period may 2009. And here you can see the value in the account, zero. Another big lie? Another complete fabrication. Reporter: Robb was charged with multiple felonies. And would plead guilty to 4 counts of making false statements, take responsibility for his actions in court, and be sentenced to 7 years in prison. From where he called us exclusively with a mea culpa for all that madness. The thing I regret is -- is kind of losing control. My lifestyle was, it was crazy. And I was hoping deep down that I could rectify the situation and -- and pay these things back. Reporter: Now between his bible study group meetings, robb says he is taking guitar lessons. Turned out robb really wasn't a gangsta or a player. Why would I spend so much money on a tour when we're not u2? Or green day. And that's one of the things that I sit in my cell and -- and -- and regret. Here's a man who wanted to be a star, but apparently didn't have the talent to do it. He had to do it through crime.

This transcript has been automatically generated and may not be 100% accurate.

{"id":21418861,"title":"Aspiring Rock Star Scammed Banks Out of Millions","duration":"8:12","description":"Act 3: Robert Mawhinney tried to pay his band's way to success with $11 million in bank loans.","section":"2020","mediaType":"Default"}